The explosive growth of mobile electronic devices, electric vehicles, drones and other technologies has driven the demand for new lightweight materials. Recently, researchers from the University of Houston and Texas A&M University reported a structured supercapacitor electrode made of reduced graphene oxide and aramid nanofibers, which is stronger and more versatile than traditional carbon-based electrodes wide.
The team research also proved that, compared with the traditional modeling method (called porous medium model), modeling based on the nanostructure of the material can more accurately understand the ion diffusion and related characteristics in the composite electrode.
"We propose that these models based on material nanostructures are more comprehensive, detailed, informative, and accurate than porous media models," said Bill H. Ardebili, associate professor of mechanical engineering at Bill Cook (UH). "More accurate modeling methods will help researchers find new, more effective nanostructured materials that can provide longer battery life and lighter energy."
The materials tested-graphene oxide and aramid nanofibers or rGO/ANF-are good choices due to their powerful electrochemical and mechanical properties. Supercapacitor electrodes are usually made of porous carbon materials, which can provide effective electrode performance.
Although the reduced graphene oxide is mainly made of carbon, the mechanical strength of aramid nanofibers can increase the versatility of the electrode in a variety of applications, including military applications. This work was funded by the US Air Force Science Institute.
Ardebili said: “What we want to convey is that traditional models based on porous media may not be accurate enough to design these new nanostructured materials and study these materials for electrodes or other energy storage devices.” This is because porous media models usually assume The pore diameter within the material is uniform, rather than measuring the different dimensions and geometric characteristics of the material.
Ardebili said: "Our suggestion is that the porous media model may be convenient, but not necessarily accurate. For the most advanced equipment, we need a more accurate model to better understand and design new electrode materials."